Just got done doing the intakes on a 99 Grand Prix. Started right up but idles at 2500. Everything worked before and appeared ok during installation. Any ideas? Thanks, Joe

High idle is often caused by a vacuum leak. Check the PCV valve to make sure there is only one o-ring under it and a big one on the chamber top. Look around for hoses or vacuum fittings you may have forgotten to re-connect. Make sure the idle control valve connector is in place.

_________________




1998 3.8 Dodge Caravan 214K
2000 3.3 Dodge Caravan 175K
1949 Plymouth Special Deluxe 4-dr sedan 25K (needs some work!)

Bill, I followed your write up on the intake through the whole process. A great help!
Rechecked again and again all the connections and vac fittings and couldn't see anything. I am wondering about the iac and tps. When I unplug the iac no difference in idle. When I unplug the tps, idle drops down to between 700 & 800 on the tach in park, aroung normal. Once plugged back in it drove normal on a test drive but started to climb again the next time out. TPS problem, and am I ok on the vac leak since it idles fine unplugged?
Thanks, Joe

It is possible to get the tang on the wrong side of the spring lever if you disassembled the TPS. But I am not really sure on how to troubleshoot, so, let me get someone smarter to help you, Joe.

_________________




1998 3.8 Dodge Caravan 214K
2000 3.3 Dodge Caravan 175K
1949 Plymouth Special Deluxe 4-dr sedan 25K (needs some work!)

Did you have the TPS off? If so, take it off again to recheck it. Reinstall the TPS from the 2 o'clock position and rotate into position. check out this video.

Even if the TPS is correctly installed, it might still by your issue. I have dozens here if you need one.

_________________
Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 55k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 95k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 260k | Official Bonneville Hauler

Ok, the tps was in the right position like in the video. This is what happens; I start it and within seconds the idle climbs into the low 2's, next I disconnect the tps and the idle drops to normal, so with it still running I plug tps back in, idle remains good and it operates normal through all driving conditions until it's shut off. Then the process needs repeating.
Without those scan tools and the know how to use them I'm tempted to R&Ring the sensors, or is it time to take it in?
Thanks for the help.

I'll mail you a spare TPS, PM me your address.

_________________
Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 55k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 95k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 260k | Official Bonneville Hauler

Sorry I put this reply off for so long, but a big thank you was over due to bill buttermore and harofreak00 for their help with my gasket swap and tps cure. Great write up on the gasket job by Bill and a working tps from harofreak00. The tps worked no more idle problems.

Thanks again,
Joe

This smells like my issue where my LeSabre will randomly rev up to 2k+ RPM at idle. Darned cheap replacement junk TPS. Time to warranty it at Advance.

_________________
2012 Chevrolet Cruze Eco - Current car

1999 Buick LeSabre Custom - Former car

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.